Concrete pumping machine

ABSTRACT

A concrete pumping machine having an elongated concrete pumping cylinder and a concrete supply hopper is provided with an inlet conduit for supplying concrete from the hopper to the cylinder and an outlet conduit for discharging the concrete from the cylinder. The inlet and outlet conduits are disposed substantially perpendicularly, and an arcuate valve blade is pivotally mounted for swinging movement into and out of the flow paths through the inlet and outlet conduits for selectively opening the inlet conduit while closing the outlet conduit and for closing the inlet conduit while opening the outlet conduit. A blade seal housing is mounted on each of the conduits for slidably receiving the swinging valve blade, and each seal housing is provided with an elongated generally rectangular opening through which the blade moves. A sealing gasket and an oil-absorbent felt pad are mounted within each housing adjacent the opening, and a hardened steel liner is positioned in the housing to protect the housing from the moving blade. The blade is mounted for arcuate movement on a pivotally mounted yoke, which is powered by a pair of double-acting hydraulic piston and cylinder assemblies, and the piston of the concrete pumping cylinder is also powered by a double-acting hydraulic piston. Suitable control means are provided for coordinating the movement of the blade-operating pistons with the movement of the pumping piston so that the pumping piston is retracted when the blade closes the outlet conduit and is extended when the blade closes the inlet conduit. The blade-operating cylinders are pivotally interconnected between the swinging yoke and the pump frame, and a hydraulic pilot valve is mounted for movement with the bladeoperating cylinder to maintain a substantially constant relationship between the pilot valve and the cylinder.

lJnited States Patent Reinert [451 Mar.211,1972

[54] CONCRETE PUMPING MACHINE Gerald ll. Reinert, Cold Spring, Ky.

[73] Assignee: Desa Industries, Inc., Cockeysville, Md.

[22] Filed: Aug. 25, 1970 [2 1] Appl. No.: 66,744

[72] Inventor:

Related US. Application Data [631 Continuation-in-part of Ser. No. 875,439, Nov. 10,

Primary Examiner-Robert M. Walker Attorney-Dawson, Tilton, Fallon & Lungmus [57] ABSTRACT A concrete pumping machine having an elongated concrete pumping cylinder and a concrete supply hopper is provided with an inlet conduit for supplying concrete from the hopper to the cylinder and an outlet conduit for discharging the concrete from the cylinder. The inlet and outlet conduits are disposed substantially perpendicularly, and an arcuate valve blade is pivotally mounted for swinging movement into and out of the flow paths through the inlet and outlet conduits for selectively opening the inlet conduit while closing the outlet conduit and for closing the inlet conduit while opening the outlet conduit. A blade seal housing is mounted on each of the conduits for slidably receiving the swinging valve blade, and each seal housing is provided with an elongated generally rectangular opening through which the blade moves. A sealing gasket and an oil-absorbent felt pad are mounted within each housing adjacent the opening, and a hardened steel liner is positioned in the housing to protect the housing from the moving blade. The blade is mounted for arcuate movement on a pivotally mounted yoke, which is powered by a pair of doubleacting hydraulic piston and cylinder assemblies, and the piston of the concrete pumping cylinder is also powered by a doubleacting hydraulic piston. Suitable control means are provided for coordinating the movement of the blade-operating pistons with the movement of the pumping piston so that the pumping piston is retracted when the blade closes the outlet conduit and is extended when the blade closes the inlet conduit. The blade-operating cylinders are pivotally interconnected between the swinging yoke and the pump frame, and a hydraulic pilot valve is mounted for movement with the blade-operating cylinder to maintain a substantially constant relationship between the pilot valve and the cylinder.

15 Claims, 10 Drawing Figures Patented March 21, 1972 5 Sheets-Sheet l GERALD H. REINERT Patented March 21, 1972 3,650,641

5 Sheets-Sheet 2 LL I g l VEN'MK GERALD H. REINERT BY Patented March 21, 1972 3,650,641

5 Sheets-Sheet 5 ii a:

FIG. 8

Patented March 21, 1972 5 Shoots-Shoot 4 k .0 v W GERALD H. REINERT wO mm Patented March 21, 1972 5 Shoots-Sheet 5 INVENTOR: GERALD H. REINERT BY:

ATT'Y CONCRETE PUMPING MACHINE RELATED APPLICATION This is a continuation-in-part of my prior copending application entitled Concrete Pumping Machine, Ser. No. 875,439,filed Nov. 10, 1969.

BACKGROUND This invention relates to concrete pumping machines, and more particularly, to a concrete pumping machine in which a single valve member is swingably mounted for opening and closing both the inlet and outlet conduits.

Concrete pumping machines conventionally include an elongated concrete pumping cylinder which slidably receives a concrete pumping piston. The concrete cylinder is connected to a source of concrete by an inlet conduit, and a gating valve is provided for opening the inlet conduit when the pumping piston is retracted to permit concrete to be drawn from the supply hopper into the cylinder. The concrete cylinder also communicates with an outlet conduit which is adapted to be connected to a pipe which conducts the concrete to the placement site. This outlet conduit is also provided with gating means which closes the outlet conduit when the pumping cylinder is being charged and which opens the outlet conduit when the pumping piston moves forwardly to pump the concrete into the pipe. When the piston is pumping, the gate valve for the inlet conduit is closed.

Many concrete pumping machines provide individual gating means for both the inlet and outlet conduits. Since the operation of each gating means must be coordinated with the operation of the pumping piston, the use of individual gating means for each conduit increases the complexity of the hydraulic or electrical circuitry which is used to control the gating means and the pumping means. Further, the gating means is generally enclosed within a housing attached to the conduit or within the conduit itself. It will be appreciated that material as abrasive as concrete can cause substantial wear in a relatively short period of time, and it is desirable to be able to periodically inspect the components of the gating means for wear. If the gating means is entirely enclosed, such inspection is difficult and time-consuming. Moreover, a breakdown in the gating means generally renders the pump inoperable, and replacement of components of enclosed gating means would involve considerable downtime. A number of men are generally used in placing and finishing the concrete pumped from one pumping machine, and several concrete ready mix trucks might be used to supply concrete to the machine. Accordingly, a breakdown of the pump for even a short time could be extremely costly.

While attempts have been made to provide a single gating member for both the inlet and outlet conduits, these gating members also are substantially or completely enclosed. Further, some single gate members are either partially or completely immersed in the concrete, thereby not only increasing abrasion of the gate member but presenting some obstruction to the concrete flow within the conduit.

SUMMARY The invention provides a single arcuate gating blade which is positioned exteriorly of the inlet and outlet conduits. Only that portion of the blade that is necessary to close either the inlet or outlet conduit is positioned in the path of the concrete, and the inlet and outlet gating portions of the blade are alternately visible for inspection when, respectively, the outlet and inlet conduits are closed. The inlet and outlet conduits are disposed substantially perpendicularly, and the arcuate blade moves in a simple swinging and knifing movement into and out of the flowpath of the concrete. Once a conduit is closed, there is no further movement of concrete past the blade which would cause abrasion or wear. The blade slides into and out of seal boxes which are disposed in the flow path of the concrete, and a urethane sealing gasket and an oil-absorbent pad are mounted in the seal box adjacent the blade opening. The sealing gasket substantially prevents the leakage of concrete from the seal box and wipes the blade as it retracts to open the flow passage in the seal box while the pad lubricates the blade and prevents hardening of any concrete that may be retained thereon. The interior of the seal box is reinforced and protected from the abrasive action of the moving blade by a replaceable hardened steel liner. The blade is boltably mounted on a swinging yoke, and the components of the seal box are enclosed by boltably mounted retainer plates. The blade, sealing gasket, and felt pad can be examined without interfering with the operating of the pump, and a malfunction or breakdown can therefore be anticipated, Since the blade is mounted exteriorly of the conduits, replacement of the blade or the components of the seal box when needed is relatively simple and requires little downtime. Further, the exteriorly mounted blade can be reinforced as needed to withstand the back pressure of the concrete on the outlet gating portion of the blade when the pumping cylinder is being charged and to withstand the pressure on the inlet gating portion of the blade when the cylinder is discharging.

DESCRIPTION OF THE DRAWING FIG. 1 is a fragmentary perspective view of a concrete pump formed in accordance with the invention;

FIG. 2 is a fragmentary sectional view taken along the lines 2-2 of FIG. 1;

FIG. 3 is a fragmentary front elevational view of FIGS. I and 2; v

7 FIG. 4 is an enlarged fragmentary sectional view of a portion of FIG. 2;

FIG. 5 is an exploded view of the inlet seal box;

FIG. 6 is a top plan view of the sealing gasket;

FIG. 7 is a top plan view of the blade yoke plate;

FIG. 8 is a front elevational view of the yoke plate of FIG. 7;

FIG. 9 is a side elevational view of the yoke plate; and

FIG. 10 is a fragmentary plan view of one of the bladeoperating pistons and an associated pilot valve.

DESCRIPTION OF SPECIFIC EMBODIMENT Referring to FIG. I, the numeral 15 designates generally a concrete pump which includes a frame 16 and a concrete supply hopper 17. The frame can be mounted on wheels for towing or can be mounted directly on a truck. The concrete hopper 17 supplies concrete to a pair of identical pumping assemblies l8 and 19 which are operated in tandem so that one pumping assembly is pumping concrete while the other pumping assembly is being charged with concrete from the supply hopper.

Referring now to FIG. 2, the pumping assembly I9 is seen to include communicating inlet and outlet conduits 20 and 21, respectively, which are welded together and extend perpendicularly. The rear end of the outlet conduit includes an attaching flange 22 which is bolted to an attaching flange 23 on an elongated concrete pumping cylinder 24. A concrete pumping piston 25 is slidably received in the pumping cylinder and is driven by piston rod 26 which is connected to a hydraulically operated driving piston 27 slidably disposed in hydraulic cylinder 28. The piston rod 26 extends through a pair of flange plates 29 and 30 on the concrete pumping cylinder 24 and the hydraulic cylinder 28, respectively, which are bolted together to connect the two cylinders, and the hydraulic cylinder is provided with suitable sealing means about the piston rod 26. The concrete pumping piston and cylinder and the hydraulic driving piston and cylinder are conventional and well known in the art, and detailed descriptions thereof is believed unnecessary.

A generally boxlike inlet seal box or housing 31 is mounted on the top of the inlet 19, and supply conduit 32 connects the inlet seal box with the hopper 17. An outlet seal box 33 is attached to the forward or discharge end of the outlet conduit, and a stub conduit or discharge pipe 34 may be attached to the forward end of the seal box to permit the pumping assembly to be connected to conventional concrete pumping pipes.

An arcuately shaped gating blade which is generally rectangular in transverse cross section is mounted for arcuate swinging movement on yoke plate 36 which is secured to a pair of arms 37 and 38. Referring to FIG. 3, the lower end of each of the arms 37 and 38 is swingably mounted by means of a trunnion bolt 39 which is threaded into a cylindrical mounting bushing 40 welded to the outlet conduit.

Double-acting hydraulical cylinders 41 and 42 are pivotally mounted on the frame 16 and slidably receive pistons 43 and 44, respectively, which are pivotally attached to the swinging arms 37 and 38. When the pistons 43 and 44 are retracted as shown in FIGS. 1-3, the gating blade 35 is positioned in the flow passage defined by the supply conduit 32, seal box 31 and inlet conduit 20 to close the inlet conduit from the supply hopper. When the pistons are extended, the gating blade is swung downwardly into the seal box 33 to close the outlet conduit 21 from the discharge pipe 34.

Similarly, pumping assembly 18 includes inlet and outlet conduits and 51, inlet seal box 52 and outlet seal box 53, supply conduit 54 and discharge pipe 55. An arcuate gating blade 56 is mounted for swinging movement into and out of the seal boxes by yoke 57 which includes a yoke plate 58 and a pair of swinging arms 59. A pair of double-acting piston and cylinder assemblies 60 and 61 are secured to the frame 16 and the swinging arms 59 for powering the gating blade 56 into and out ofthe associated seal boxes.

Each of the gating blades 35 and 56 are arcuately shaped and extend along an arc of about 90. The blade may be rolled from straight stock and then heat treated by carburizing and case hardening. In one specific embodiment, the blades were formed from ASTM A 283 steel which was deep casehardened to a depth of about 50 to about 60 mils. The resulting blades had a Rockwell hardness of about R 6O.

Referring to FIGS. 7-9, the yoke plate 36 may be formed from generally flat plate which is machined to provide central portion 65 having an arcuate upper surface 65a having the same radius as the radius of the blade. The central portion 65 is provided with a plurality of threaded bolt holes 66 for receiving attaching bolts 67 (FIG. 1) which secure the blade to the plate, and the side portions of the plate are provided with bolt openings 68 for attaching bolts 69 which secure the plate to the swinging arms 37 and 38. A central opening 70 may be provided between the bolt openings 68 for receiving a locating stud 71 (FIG. 2) which extends upwardly from the swinging arm.

Referring now to FIGS. 4 and 5, the inlet seal box includes outer parallel side walls 75 and 76 which are welded to a rear wall 77 extending therebetween. Top and bottom plates 78 and 79 are welded to the side and rear walls, and each of the top and bottom plates is provided with a central opening therethrough of the same size as the bore of the inlet conduit 20 and the supply conduit 32. The side, rear, top and bottom walls of the seal box define a boxlike interior chamber 80 which communicates with the inlet conduit 20 and supply pipe 32 to form part of the flow passage for the concrete.

A generally U-shaped deep casehardened steel liner 81 having side walls 82 and 83 and end wall 84 is received relatively snugly in the interior chamber 80 of the seal box and secured therein by bolts (not shown) which extend through bolt openings 85 in the side walls of the seal box and into bolt openings 86 in the liner. The side walls of the liner terminate rearwardly of the forward end of the side walls 75 and 76 of the seal box, and a sealing gasket 87 is pressed against a pair of elongated, spaced-apart gasket mounting bars 88 which extend between the liner side walls by gasket retaining plate 89. The sealing gasket 87 is generally rectangular (FIG. 6) and extends between the side walls of the seal box. An elongated generally rectangular central opening 90 is provided through the gasket, and the length of the opening is approximately the same as the width of the gating blade. The gasket is shown in transverse cross section in FIG. 4 and is seen to include an enthickened central portion 91 (FIG. 5) which provides a pair of tapered sealing lips 92 and 93 which press against the blade. The walls 94 and 95 which define the central opening 90 of the gasket have approximately the same curvature as that of the blade, and before the blade is inserted through the central opening 90 the spacing between the sealing lips 92 and 93 is slightly less than the thickness of the blade so that good wiping action is provided by the lips when the blade moves therebetween. The gasket is preferably formed of flexible resilient material, and one specific gasket was formed of a urethane plastic available from Parkway Products of Cincinnati, Ohio under the trade name Partek. The durometer rating of the urethane should be above 80, and l have found that a durometer rating of 90 provides good results.

As can be seen best in FIG. 4, the transverse dimension of the gasket 87 is slightly less than the distance between the upper and lower walls 78 and 79 of the seal box so that during assembly of the seal box the position of the gasket within the seal box can be varied depending upon the alignment of the gating blade. The thickness of the end portions of the gasket beyond the enthickened central portion thereof is such that when the gasket retaining plate 89 is held against the forward ends of the side walls 75 and 76 of the seal box, these end portions of the gasket will be compressed slightly against the mounting bars 88 to hold the gasket in the desired position and to provide a seal around the periphery of the gasket.

An oil-absorbent pad 96 of felt or like material is held against the gasket retainer plate 89 by pad retainer plate 97, which is provided with a rearwardly facing recess 98 for receiving the pad. The gasket retaining plate and the pad retaining plate are removably secured to the seal box 31 by bolts 99 which pass through bolt openings 100 in the pad retaining plate and 101 in the gasket retaining plate and into threaded openings 102 in the wall of the seal box.

Referring to FIG. 4, the retainer plates 89 and 97 are provided with generally rectangular blade openings 103 and 104, respectively, which are slightly wider than the thickness of the blade 35 and which are staggered slightly to accommodate the arcuate movement of the blade. The felt pad 96 is also provided with a central opening 105 which is substantially the same size as, or slightly smaller than, the blade 35 to wipe the blade as it moves therethrough. Lubricating oil is applied to the pad 96 through oil fitting 106 which communicates with the recess 98.

A hopper-attaching plate 110 is secured to the top wall 78 of the seal box by bolts 111 which extend through the side walls of the seal box into an attaching plate 112 which is welded to the inlet conduit 20. The attaching plate 110 is provided with a central opening having first a portion 113a of approximately the same diameter as the diameter of the central opening through the top wall 78 and a radially enlarged potion 1l3b which is offset from the opening 113a by shoulder 114. The supply pipe 32 is received in the opening l13b and supported by shoulder 114, and the supply pipe is removably secured within the attaching plate 110 by bolts 115. An O-ring 116 is received in an annular recess 117 in the outer wall of the supply pipe 32 and provides a sealing engagement between the supply pipe and the inlet seal box.

The rear ends of the blade-operating cylinders 41 and 42 are pivotally connected to bushings 120 which are bolted to a support bar 121 extending behind the inlet conduit. The support bar 121 in turn is bolted to rearwardly and upwardly angled extensions 75 and 76, respectively, of the side walls 75 and 76 of the seal box. The forward end of each of the bladeoperating pistons is pivotally secured to one of the swinging arms by a clevis 122 (FIGS. 1 and 10). Since the blade-operating cylinders and pistons are pivotally secured to both the frame 16 and the swinging arms, the inclination of the cylinder and piston can change freely as the arms swing to move the blade into and out of the seal boxes.

The outlet seal box 33 is substantially identical to the inlet seal box 31, and a detailed description thereof is unnecessary. The primary difference between the outlet seal box and the inlet seal box is that the angled extensions 75 and 76 of the side walls of the inlet seal box are unnecessary for the side walls of the outlet seal box. In all other respects, the outlet seal box is identical.

The pumping assembly 18 is identical to the pumping assembly l9, and a description of the seal boxes 52 and 53 and the mounting of the gating blade 56 is also unnecessary.

Referring to FIGS. 2 and 4, the gating blade 35 is illustrated in position to close the flow passage through the inlet conduit 20 and to open the flow passage through the outlet conduit 21. With the blade inthis position, the concrete pumping piston could be powered forwardly to pump the concrete from the concrete pumping cylinder 24 through the outlet conduit 21 and discharge pipe 34. The rearward edge of the blade abuts the bottom wall 84 of the hardened steel liner, and the lips 92 and 93 of the sealing gasket, particularly the lower lip 93, are pressed against the blade 35 to prevent leakage of the concrete from the seal box. The distance between the side walls 82 and 83 of the hardened steel liner is substantially the same as the width of the blade, and some tolerance between the blade and the liner walls is acceptable because the sand and fine aggregate of the concrete will create a substantially complete material lock against passage of the concrete. For example, three thirty-seconds inch tolerance between each side of the blade and the side wall of the liner is acceptable.

When the blade-operating pistons are extended to swing the blade 35 downwardly into engagement with the bottom wall of the hardened steel liner of the outlet seal box, the blade will move out of the interior chamber 80 of the inlet box to a posi tion illustrated in phantom at 35 in FIG. 4 in which the inlet flow passage is fully opened. The blade is lubricated as it slides with respect to the felt oiling pad 96, and any concrete which escapes past the sealing gasket is thereby prevented from hardening. In this position illustrated in phantom, the blade will still be sealingly engaged by the lips 92 and 93 of the sealing gasket, and the lower portion of the blade closes the flow passage through the outlet conduit 21. The concrete pumping piston 25 may be retracted to draw concrete from the hopper into the pumping cylinder 24.

It is thus seen that substantially the entire gating portions of the blade for both the inlet and outlet flow passages move outwardly from the respective seal box during each complete stroke of the pump, and the gating portions of the blade can be readily examined to determine the extent of wear and possible malfunction. Further, the parts of the seal box most subject to wear the sealing gasket and the oiling pad can be examined through the slots 103 and 104 in the retainer plates when the machine is in operation. This can be seen in FIG. 3 in which the upper portion of the blade is broken away. The liner 81 for the seal boxes isdeep casehardened to withstand abrasion and wear, and this part will require replacement infrequently. In one specific embodiment of the invention the liners were formed of AISI M 1020 low carbon steel which was deep case hardened to a depth of about 30 to 40 mils.

Replacement of the gating blade or of any ofthe parts ofthe seal box can be accomplished quickly and easily merely by removing the blade attaching bolts 67, the bolts 99, and the retainer plates 89 and 97. If the liner 81 is to be replaced, the securing bolts which extend through the openings 85 and 86 are withdrawn to permit the liner to be removed from the box. If desired, the rear wall 77 of the box may be provided with one or two openings to permit the liner to be tapped from the rear and to loosen any grout which may have accumulated between the liner and the interior walls of the box.

The hydraulic control system for the pump coordinates the pumping assemblies 18 and 19 so that one of the pumping assemblies is pumping while the other is discharging and coordinates the blade of each pumping assembly with the hydraulic driving piston so that the pumping piston is retracted when the outlet conduit is closed and is powered forwardly when the outlet is open. Such hydraulic control systems are conventional and well known in the art, and a detailed description thereof is believed to be unnecessary. It is sufficient to say that the hydraulic control system may include four-way control valve for the two hydraulic driving cylinders and a four-way control valve for the two pairs of gate-operating hydraulic cylinders. The control valve for the driving cylinders is operatively connected to a pair of pilot valves, each of which is mounted for actuation by one of the gating means when the gating means closes the associated inlet conduit. The control valve for the gate-operating cylinders is operatively connected to a pair of pilot valves, each of which is operated by one of the hydraulic driving pistons wen the piston reaches the end of its forward stoke. While'the driving'piston of the first pump is moved forwardly by hydraulic pressure admitted through the control valve for the driving cylinders, the driving piston of the second pump is being retracted by hydraulic fluid expelled from the rod end of the first hydraulic cylinder. When the first piston reaches the end of its stroke, it trips the associated pilot valve to actuate the gate control valve to admit pressurized hydraulic fluid to the gate-operating cylinders to close the outlet conduit of the first pump and to open the outlet conduit of the second pump. When the gating means of the second pump closes the inlet conduit thereof, the associated pilot valve is actuated to move the control valve for the hydraulic driving cylinders to introduce pressurized fluid to move the driving piston of the second pump forwardly. As the second driving piston is moved forwardly, the expelled fluid retracts the first driving piston. When the second piston reaches the end of its forward stroke, the associated pilot valve is tripped to switch the position of the control valve for the blade-operating cylinders, and the positions of the gating means are again reversed. When the gating means of the first pump is swung upwardly to close the inlet conduit thereof, the associated pilot valve is tripped to change the position of the control valve for the hydraulic cylinders, and the cycle is repeated.

Referring to FIG. 1, each of the gate-operated pilot valves 125 and 126 are mounted on one of the blade-operating cylinders of each pumping assembly. Each of the pilot valves 125 and 126 includes a depressable control button 127 (FIGS. 1 and 10), which is positioned for engagement with the clevis 122 of the associated piston. When the blade has been swung upwardly to close the inlet conduit, the clevis 122 will engage the control button 127 and change the position of the control valve for the hydraulic driving cylinders. Since the pilot valve is mounted to the gate-operating cylinder, the pilot valve will move with the cylinder as the blade swings back and forth, and the clevis will always be moved straight across the operating button 127 even though the clevis is swinging in an arc. Further, back pressure on the outlet gating portion of the blade when the concrete cylinder is being charged or pressure on the inlet gating portion of the blade when the cylinder is pumping may cause the blade to move slightly radially outwardly or inwardly. However, even if this should occur, the clevis and pilot valve will move with the blade, and the possibility that the pilot will fail to be actuated when the blade is retracted is minimized.

The lubricating oil which is supplied to the felt pads of the seal boxes can be taken directly from the hydraulic control system for the pump. Referring to FIG. 1, each of the oil inlets 106 for the four seal boxes is connected to an oil metering device 128 by a conduit 129. The metering device 128 is conventional and is supplied with hydraulic fluid from one of the hydraulic conduits of the hydraulic control system. For example, the metering device 128 may be connected to the hydraulic conduits which extend between the gate pilot valves 125 and 126 and the control valve for the hydraulic driving cylinders. Each time one of the gate pilot valves is actuated, one of these hydraulic conduits will be pressurized, and the metering device 128 will supply a quantity of oil to two of the four felt pads. In one complete cycle of the pump, both pilot valves will be actuated, and a shot of oil will be supplied to each of the four felt pads.

In the particular embodiment illustrated each of the gating blades 35 and 56 was formed of a single piece of metal which extended through an arc of about However, as disclosed in my said prior copending application, each gating blade can be formed of two segments each of which extend through an are or approximately 45. Each segment would then be boltably secured to the yoke plate by four of the attaching bolts 67.

In one specific embodiment of the invention the flow passage for the concrete defined by the inlet and outlet conduits was about 7 inches, and the width of the gating blades was also about 7 inches. Each blade was about 1% inches tick, and the radius of the inner curved surface thereof was about l8 inches.

While in the foregoing specification, a detailed description of a specific embodiment of the invention was set forth for the purpose of illustration, it is to be understood tat many of the details hereingiven may be varied considerably by those skilled in the art without departing from the spirit and scope of the invention.

Iclaim:

1. In a pumping apparatus, a frame, an inlet conduit on the frame defining a flow passage and adapted to be connected to a source of material to be pumped, an outlet conduit on the frame defining a flow passage communicating with the flow passage of the inlet conduit and extending angularly therefrom, a first blade seal housing secured to the inlet conduit and a second blade seal housing secured to the outlet conduit, each of the seal housings having an outer wall extending substantially perimetrically about the associated conduit and defining an interior chamber communicating with the flow passage of the associated conduit, a portion of the outer wall of each housing being provided with an elongated slot therethrough, and an arcuately extending blade member having a pair of blade ends and being pivotally mounted on the frame for swinging movement in the plane defined by the angularly related inlet and outlet conduits, each blade end being slidably receivable in one of said slots in the inlet or the outlet seal housings whereby the blade may swing into and out of each of the seal housing chambers to alternately close and close the flow passage of each of the conduits.

2. The apparatus of claim 1 including a hardened steel liner positioned within each of said seal housings for engaging the blade when the blade moves into the seal housing to close the flow passage therethrough.

3. The apparatus of claim 2 in which each of the liners is generally U-shaped and includes a bottom wall for engaging the end of the blade and a pair of side walls spaced apart a distance slightly greater than the width of the blade.

4. The apparatus of claim 1 in which the blade is formed of deep casehardened low carbon steel.

5. The apparatus of claim 1 including a sealing gasket within each of the seal housings adjacent the elongated slot thereof, the sealing gasket being provided with a central opening therethrough with at least a portion of the gasket opening being narrower than the thickness of the blade whereby the gasket presses against the blade as the blade passes through the central opening thereof.

6. The apparatus of claim 5 in which the central opening of the gasket is defined by a pair of spaced-apart curved walls, the gasket including an enthickened central portion adjacent the central opening to provide a pair of lip portions for sealingly engaging the blade.

7. The apparatus of claim 1 including an oil-absorbent pad positioned within each of the seal housings adjacent the slot therethrough, the oil absorbent pad being provided with a central opening therethrough through which the blade moves, and means for supplying oil to the pad whereby the blade is lubricated by the pad as it moves therethrough.

8. The apparatus of claim 1 including a supply hopper for the material to be pumped and a supply conduit extending downwardly from the hopper, the first seal housing including an upper plate provided with an opening therethrough, the supply conduit being slidably received in the opening of the upper plate, and bolt means on the upper plate for releasably securing the supply conduit within said upper plate opening.

9. The apparatus of claim 1 in which said blade is secured to a pair of arms pivotally mounted on opposite sides of the outlet conduit, hydraulically operated piston and cylinder means for each of said arms for pivoting the arms, one end of each piston and cylinder means bein pivotallysecured to the associated arm and the other en of the piston and cylinder means being pivotally secured to the frame, pilot valve means secured to one of the piston and cylinder means for movement therewith as the arms are pivoted, and means secured to one of the arms for engaging the pilot valve means when the blade closes a flow passage through one of the conduits whereby the cylinder and piston means and the pilot valve means move with the engaging means as the arms pivot to move the engaging means toward the pilot valve means.

10. The apparatus of claim 1 in which the blade is generally rectangular in transverse cross section and the slot in each of the seal housings is generally rectangular, an elongated generally rectangular sealing gasket positioned within each seal housing, each sealing gasket having a generally rectangular opening therethrough for slidably receiving and sealingly engaging the blade, first retaining plate means removably secured to each housing for securing the sealing gasket to the housing, an oil-absorbent generally rectangular lubricating pad positioned against each of the first retaining plate means, the lubricating pad having a generally rectangular opening therethrough for slidably receiving the blade, second retaining plat means removably secured to each housing for securing the lubricating pad to the housing, and oil supply means on each housing for supplying oil to the pad.

11. The apparatus of claim 10 including a generally U- shaped hardened steel liner positioned within each housing, each liner having a bottom wall for engaging the end of the blade when the blade closes the flow passage through the associated housing and a pair of side walls spaced apart a distance slightly greater than the width of the blade.

12. The apparatus of claim 11 including bolt means on each housing for removably securing the liner within each housing.

13. The apparatus of claim 11 in which the gasket is supported by the side walls of the liner.

14. The apparatus of claim 11 including a pair of spacedapart gasket support bars extending between the side walls of the liner, the gasket being pressed against the gasket support bars by the first retaining plate means.

15. The apparatus of claim 1 in which each of the seal housings is generally rectangular in transverse cross secton and includes a pair of spaced-apart generally parallel side walls, a rear wall extending between the side walls and secured thereto, upper and lower plates extending generally transversely to the direction of flow and secured to the top and bottom, respectively, of the side and rear walls, each of the upper and lower plates having a central opening therethrough, and a front plate removably secured to the side walls, said elongated slot being provided through the front plate.

I V UNITED STATES PATENT OFFICE ERTWICAT 3,650,641 Dated March 21, 1972 Patent No,

Inventor(s) Gerald R inert It is certified that error appears in the above-identified patent and that said Letters'Patent are hereby corrected as shown below:

In claim 1, column 7, line 33, please change "close" to --openo In claim 10, column 8, line 34, "plat" should be plate-m Signed and sealed this 29th day of August 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents 

1. In a pumping apparatus, a frame, an inlet conduit on the frame defining a flow passage and adapted to be connected to a source of material to be pumped, an outlet conduit on the frame defining a flow passage communicating with the flow passage of the inlet conduit and extending angularly therefrom, a first blade seal housing secured to the inlet conduit and a second blade seal housing secured to the outlet conduit, each of the seal housings having an outer wall extending substantially perimetrically about the associated conduit and defining an interior chamber communicating with the flow passage of the associated conduit, a portion of the outer wall of each housing being provided with an elongated slot therethrough, and an arcuately extending blade member having a pair of blade ends and being pivotally mounted on the frame for swinging movement in the plane defined by the angularly related inlet and outlet conduits, each blade end being slidably receivable in one of said slots in the inlet or the outlet seal housings whereby the blade may swing into and out of each of the seal housing chambers to alternately close and close the flow passage of each of the conduits.
 2. The apparatus of claim 1 including a hardened steel liner positioned within each of said seal housings for engaging the blade when the blade moves into the seal housing to close the flow passage therethrough.
 3. The apparatus of claim 2 in which each of the liners is generally U-shaped and includes a bottom wall for engaging the end of the blade and a pair of side walls spaced apart a distance slightly greater than the width of the blade.
 4. The apparatus of claim 1 in which the blade is formed of deep casehardened low carbon steel.
 5. The apparatus of claim 1 including a sealing gasket within each of the seal housings adjacent the elongated slot thereof, the sealing gasket being provided with a central opening therethrough with at least a portion of the gasket opening being narrower than the thickness of the blade whereby the gasket presses against the blade as the blade passes through the central opening thereof.
 6. The apparatus of claim 5 in which the central opening of the gasket is defined by a pair of spaced-apart curved walls, the gasket including an enthickened central portion adjacent the central opening to provide a pair of lip portions for sealingly engaging the blade.
 7. The apparatus of claim 1 including an oil-absorbent pad positioned within each of the seal housings adjacent the slot therethrough, the oil absorbent pad being provided with a central opening therethrough through which the blade moves, and means for supplying oil to the pad whereby the blade is lubricated by the pad as it moves therethrough.
 8. The apparatus of claim 1 including a supply hopper for the material to be pumped and a supply conduit extending downwardly from the hopper, the first seal housing including an upper plate provided with an opening therethrough, the supply conduit being slidably received in the opening of the upper plate, and bolt means on the upper plate for releasably securing the supply conduit within said upper plate opening.
 9. The apparatus of claim 1 in which said blade is secured to a pair of arms pivotally mounted on opposite sides of the outlet conduit, hydraulically operated piston and cylinder means for each of said arms for pivoting the arms, one end of each piston and cylinder means being pivotally secured to the associated arm and the other end of the piston and cylinder means being pivotally secured to the frame, pilot valve means secured to one of the piston and cylinder means for movement therewith as the arms are pivoted, and means secured to one of the arms for engaging the pilot valve means when the blade closes a flow passage through one of the conduits whereby the cylinder and piston means and the pilot valve means move with the engaging means as the arms pivot to move the engaging means toward the pilot valve means.
 10. The apparatus of claim 1 in which the blade is generally rectangular in transverse cross section and the slot in each of the seal housings is generally rectangular, an elongated generally rectangular sealing gasket positioned within each seal housing, each sealing gasket having a generally rectangular opening therethrough for slidably receiving and sealingly engaging the blade, first retaining plate means removably secured to each housing for securing the sealing gasket to the housing, an oil-absorbent generally rectangular lubricating pad positioned against each of the first retaining plate means, the lubricating pad having a generally rectangular opening therethrough for slidably receiving the blade, second retaining plat means removably secured to each housing for securing the lubricating pad to the housing, and oil supply means on each housing for supplying oil to the pad.
 11. The apparatus of claim 10 including a generally U-shaped hardened steel liner positioned within each housing, each liner having a bottom wall for engaging the end of the blade when the blade closes the flow passage through the associated housing and a pair of side walls spaced apart a distance slightly greater than the width of the blade.
 12. The apparatus of claim 11 including bolt means on each housing for removably securing the liner within each housing.
 13. The apparatus of claim 11 in which the gasket is supported by the side walls of the liner.
 14. The apparatus of claim 11 including a pair of spaced-apart gasket support bars extending between the side walls of the liner, the gasket being pressed against the gasket support bars by the first retaining plate means.
 15. The apparatus of claim 1 in which each of the seal housings is generally rectangular in transverse cross secton and includes a pair of spaced-apart generally parallel side walls, a rear wall extending between the side walls and secured thereto, upper and lower plates extending generally transversely to the direction of flow and secured to the top and bottom, respectively, of the side and rear walls, each of the upper and lower plates having a central opening therethrough, and a front plate removably secured to the side walls, said elongated slot being provided through the front plate. 